Add admin features, responsive UI, user reviews, visit stats, and channel-colored markers

- Admin: video management with Google Maps match status, manual restaurant mapping, restaurant remap on name change
- Admin: user management tab with favorites/reviews detail
- Admin: channel deletion fix for IDs with slashes
- Frontend: responsive mobile layout (map top, list bottom, 2-row header)
- Frontend: channel-colored map markers with legend
- Frontend: my reviews list, favorites toggle, visit counter overlay
- Frontend: force light mode for dark theme devices
- Backend: visit tracking (site_visits table), user reviews endpoint
- Backend: bulk transcript/extract streaming, geocode key fixes
- Nginx config for production deployment

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/run_api.py

@@ -6,4 +6,11 @@ load_dotenv()
 import uvicorn
 
 if __name__ == "__main__":
-    uvicorn.run("api.main:app", host="0.0.0.0", port=8000, reload=True)
+    uvicorn.run(
+        "api.main:app",
+        host="0.0.0.0",
+        port=8000,
+        reload=True,
+        workers=1,
+        limit_concurrency=20,
+    )